As a pastor I get questions about life after death, communicating with the dead, psychics, fortune-telling and the like. I think gotquestions.org explains it all best below.
Question: “What happens after death?”
Answer: Within the Christian faith, there is a significant amount of confusion regarding what happens after death. Some hold that after death, everyone “sleeps†until the final judgment, after which everyone will be sent to heaven or hell. Others believe that at the moment of death, people are instantly judged and sent to their eternal destinations. Still others claim that when people die, their souls/spirits are sent to a “temporary†heaven or hell, to await the final resurrection, the final judgment, and then the finality of their eternal destination. So, what exactly does the Bible say happens after death?
First, for the believer in Jesus Christ, the Bible tells us that after death believers’ souls/spirits are taken to heaven, because their sins are forgiven by having received Christ as Savior (John 3:16, 18, 36). For believers, death is to be “away from the body and at home with the Lord†(2 Corinthians 5:6-8; Philippians 1:23). However, passages such as 1 Corinthians 15:50-54 and 1 Thessalonians 4:13-17 describe believers being resurrected and given glorified bodies. If believers go to be with Christ immediately after death, what is the purpose of this resurrection? It seems that while the souls/spirits of believers go to be with Christ immediately after death, the physical body remains in the grave “sleeping.†At the resurrection of believers, the physical body is resurrected, glorified, and then reunited with the soul/spirit. This reunited and glorified body-soul-spirit will be the possession of believers for eternity in the new heavens and new earth (Revelation 21-22).
Second, for those who do not receive Jesus Christ as Savior, death means everlasting punishment. However, similar to the destiny of believers, unbelievers also seem to be sent immediately to a temporary holding place, to await their final resurrection, judgment, and eternal destiny. Luke 16:22-23 describes a rich man being tormented immediately after death. Revelation 20:11-15describes all the unbelieving dead being resurrected, judged at the great white throne, and then being cast into the lake of fire. Unbelievers, then, are not sent to hell (the lake of fire) immediately after death, but rather are in a temporary realm of judgment and condemnation. However, even though unbelievers are not instantly sent to the lake of fire, their immediate fate after death is not a pleasant one. The rich man cried out, “I am in agony in this fire†(Luke 16:24).
Therefore, after death, a person resides in a “temporary†heaven or hell. After this temporary realm, at the final resurrection, a person’s eternal destiny will not change. The precise “location†of that eternal destiny is what changes. Believers will ultimately be granted entrance into the new heavens and new earth (Revelation 21:1). Unbelievers will ultimately be sent to the lake of fire (Revelation 20:11-15). These are the final, eternal destinations of all people—based entirely on whether or not they had trusted Jesus Christ alone for salvation (Matthew 25:46; John 3:36).‎ The scripture he will judge “the quick and the dead” (Acts 10:42; 2 Timothy 4:1) is a reference to the final judging of those living (quick) at the time of Christ’s return and those who have died (dead) and been resurrected for the final judgment.
Question: “But what does the Bible say about praying to / speaking to / talking to the dead?”
Answer: Praying to the dead is strictly forbidden in the Bible. Deuteronomy 18:11tells us that anyone who “consults with the dead†is “detestable to the Lord.†The story of Saul consulting a medium to bring up the spirit of the dead Samuel resulted in his death “because he was unfaithful to the LORD; he did not keep the word of the LORD and even consulted a medium for guidance†(1 Samuel 28:1-25; 1 Chronicles 10:13-14). Clearly, God has declared that such things are not to be done.
Consider the characteristics of God. God is omnipresent—everywhere at once—and is capable of hearing every prayer in the world (Psalm 139:7-12). Every Sunday a million prayers are offered up to God from around the world at the same time and He hears them all.  A human being, on the other hand, does not possess this attribute. Also, God is the only one with the power to answer prayer. In this regard, God is omnipotent—all powerful (Revelation 19:6). Certainly this is an attribute a human being—dead or alive—does not possess. Finally, God is omniscient—He knows everything (Psalm 147:4-5). Even before we pray, God knows our genuine needs and knows them better than we do. Not only does He know our needs, but He answers our prayers according to His perfect will.
So, in order for a dead person to receive prayers, the dead individual has to hear the prayer, possess the power to answer it, and know how to answer it in a way that is best for the individual praying. Only God hears and answers prayer because of His perfect essence and because of what some theologians call His “immanence.†Immanence is the quality of God that causes Him to be directly involved with the affairs of mankind (1 Timothy 6:14-15); this includes answering prayer.
Even after a person dies, God is still involved with that person and his destination.Hebrews 9:27 says so: “…Man is destined to die once, and after that to face judgment.†If a person dies in Christ, he goes to heaven to be present with the Lord (2 Corinthians 5:1-9, especially verse 8); if a person dies in his sin, he goes to hell, and eventually everyone in hell will be thrown into the lake of fire (Revelation 20:14-15).
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